//
//  ST_Foudation+Bt.swift
//  BTVideo
//
//  Created by DouLei on 2019/7/9.
//  Copyright © 2019 DouLei. All rights reserved.
//

import Foundation


extension Collection {
    
    /// Returns the element at the specified index if it is within bounds, otherwise nil.
    subscript (safe index: Index) -> Element? {
        return indices.contains(index) ? self[index] : nil
    }
}
